blizzard81
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Posts posted by blizzard81
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The biggest trend today has been the introduction of a possible Scandi High at the end of the coming week. ECM has been toying
with this over the last couple of days and I believe the GFS is now entertaining the idea of this. I believe the possibilty of a Scandi
High is coming about as a result of some very cold uppers in Scandinavia over the next few days and the models will not get to grips with
this until much nearer the time. Put it this way, I would not be suprised to see the 00z models showing a rebust Scandi High by the
end of this coming week thus advecting some very cold air our way. This also ties in with Chio's posts with regards to Cohen re Strat warming.
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The ECM op is a car crash. One thing I have noticed over the years which seems to corelate with mild weather over the UK is
a stubborn high pressure system over north east Canada. This seems to do us no favours at all and is omnipresent throughout the ECM op.
I have got a niggling feeling that this is going to be one of those oh so nearly winters where although the patterns look positive for cold, things
just do not fall into place at the right time. BFTP mentioned this a few weeks ago. I think he mentioned a previous winter (2002 ?) which was one such example.
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I haven't posted on here for a few weeks, been checking the model runs every few days and at the moment, they are absolutely hideous for cold and snow lovers! I hope january and february show signs of turning a lot colder. the ensembles make for bad viewing at the moment!
Well with a quote like that, could you please not post for another few weeks, lol
Only yokin!!The only thing giving me hope at the moment is we still have time for the models to revert back to cold in time for Xmas. However,
only another 24 - 48 hours at most.
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Bear in mind the analyses prepared by UKMO at that range take no notice of GFS for reasons previously outlined. The 00z suite analysis due any minute now from Ops Centre. I'll advise if there's any key change of thinking.
That explains my query earlier - I thought the analysis you posted earlier was based on the 00z suite.
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I think the 12z's will put the final nail in the cold coffin, would be somewhat ironic though to see the 6z ENS produce the goods, I've seen this before, blow torch OP = betters ensembles, freezing OP = rubbish ens.
We'll see anyway, knowing the models recently we'll probably have yet another twist today.
Yes, sometimes you get the feeling that the models are toying with us and leading us on a constant merry go round!!
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I think it probably comes down to this point in the ECM:
The model tries to take some energy se but fails in the next frame, i'd say that this is last chance saloon time, if you don't get energy heading se and splitting the trough then IMO thats game over.
Because after this with the energy going ne the Azores high ridges ne and once that happens its really a long road back to cold.
Yes Nick, the difference between the ECM operational and control of this morning when compared to yesterdays ECM runs is that yesterday
they were keen to send the energy south east into Europe but today they are having none of it and the ECM has clearly moved towards GFS.
We are also 24 hours nearer to the eventual outcome so we are running out of time for the ECM to revert back to what it was showing yesterday.
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This is all getting very bizarre!
I just don't see how you get to an easterly with the jet tilted sw/ne and pressure rises over Iberia.
The upstream pattern amplifies at completely the wrong moment, this needs to happen well before the next low exits the USA and phases with the one near the UK.
In terms of those transient snow chances mentioned by Ian F this would suggest the Russian block extends sufficiently west to help carve out a se surface flow off the continent.
And some energy being diverted se near the UK. Its a small straw to clutch onto but really we'd need to see some big changes in the earlier timeframes.
Absolutely. I'm not Meto bashing here but I again get that recurring feeling of the Meto always being 24 hours behind everyone else - behind most
people on this forum anyway! If this was yesterday morning, I would understand Meto's analysis (kindly given to us by Fergie which is much appreciated) However, things have really taken a turn for the worse for coldies with the overnight operationals - and now backed up by the 6z.
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The BOM is where it's at tonight, perfect evolution as the Arctic high sets up home close to northern Norway sending the shortwaves packing towards Biscay. Shame it's just the BOM!
It may just be the BOM but no one can deny it's consistency these last few days. The question is - consistently correct or
consistently wrong?? I don't think we have long to wait for the answer now. I am as confused as the models right now but there is
something in the back of my mind that tells me the BOM performed well in the run up to the Nov/Dec 2010 cold spell or was it the 2009/2010 winter
or indeed both? It would be great to get an update from GP right now so he can give us his thoughts on which models he thinks are in tune with his
thoughts for the next ten days.
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http://www.meteociel...H1-240.GIF?15-0
Excellent 240 Chart from the ECM & I expect the ECM ensuemble suite to move to a drop from day 9/10 tonight.
Lets be clear though its not VERY cold at the surface, with that gentle easterly tug I think we get quiet misty weather with a range from 3-8C.
Post 240 though the dice are loaded... The mid-atlantic block has now seperated the jet & there is plenty of energy in the southern branch.
What 264 would show would be a block of heigher heights extending from the main block out of Scandi - linking towards Canada- VERY flat & elongated, so the UK under gentle Easterlies, where as places like iceland & southern greenland would be in a mean Westerly flow-
POST that a HIGH chance of retrograde out to greenland with a sharp inflection of the jet- seen it many times before.
The ECM is still my favoured model here & continues to be in projected Easterly incursions...
The shuffle is now turning into a walk...
S
The thing I like most about that chart is the total lack of an azores high. Always a good sign to me
in terms of cold further down the line.
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GEFS mean height anomaly at day 10.
Note the omega signature there in the western Atlantic as the jet flow splits and sets up the ridge development into Greenland. Whilst this is the most agressive of the GFS runs today in developing this block, it is not new and has been there on the ensemble means for the last few days.
We are entering a window where a holy trinity are at play which will set the scene for some rarified synoptics...MJO wave entering phase 8...poleward +AAM tendency...seasonal wavelength changes to the pattern dictated by the ridge in the Pacific. All of this at a time when the troposheric vortex is going to take repeated hits from wave 2 activity.
The 12z GEFS ends like this:
That mean anomaly includes some peturbations which flatten out the Pacific ridge and can be readily discounted. That makes this an understatement of the height anomaly, which is extremely strong at that range.
However, to take this back to earth somewhat, it's just one GFS run so we need to the ECM and other global models picking up the lifting out of the vortex from Canada and split flow developing in the Atlantic t192 through t240.
Hi Stewart, am I correct in saying the 12z ECM operational delivered in terms of split flow in the Atlantic at the back end of it,s run?
Or am I reading it wrong?
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Is that cross polar ridging I see on the ECM 240 chart? - from the pacific right through to Scandi!
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I'm saying we tend to use 00 & 12z whenever either are available but the other runs shouldn't be loosely discounted or devalued per se (albeit in any case, UKMO invariably prefer ECMWF as their pointer versus GFS, in my experience)
Thank you Ian, much appreciated.
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I think im right in saying that out of all the GFS model runs the 12Z is most accurate followed by the 0Z. This doesn't mean the 18Z is wrong though and I hope this continues in future outputs.
Yes, I tend to take the 12z and 00z far more seriously but like you say, lets hope the 18z is the start of trend by the GFS - For once!!
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As for this 'pub run' 18z GFS thing: to my knowledge the only difference between 06z / 18z runs and those initiated at 00z / 12z by NOAA is absence of US radiosonde network data input. In any event of course, thIs single run output remains unconvincing until we see better continuity.
Are you saying that this missing data is not all that crucial?
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Nov/Dec was a once in a 100 years event. It's a shame to see some "respected" posters alluding to it, especially from the 18z of all things! It really is a shame when this thread loses all sense of reason between October & March every year & for some reason, this year seems even worse than usual.
CFS 3 and 4 weekly ensembles back up GP's thoughts with regards to blocking signal over southern Greenland/Iceland.
This has had a few wobbles over the last couple of days but it has now reverted to what it was consistantly showing
a week or so ago. Good news indeed. Sorry, didn't mean this to be a response to Davehsug - hit the wrong quote icon!!
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still some negativity across these threads atm - the pattern is of an emerging cold theme towards the months end, in time for the start of winter, what more could we ask for? (for it to happen, is the obvious answer). Best run of the season so far. I don't buy this 'pub run' suggestion that the 18Z is any less valid than the others, or that the ECM is backing away. Chops and changes are inevitable at this range so let the models sort themselves out and come back in a week if people can't handle the topsy turvy nature of UK winters.
Not a case of not handling the topsy turvy nature of UK winters. Just stating a fact that the ECM 12z ensembles are a big
dissapointment for cold fans this evening. If we are to see a trend, the best indicator is the ECM ensemble suite and certainly not the 18z.
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11 days & how things can change once we get the right retrograde....
it will probably take 3 goes-
S
Looks like a much sweeter version of the ECM 12z operational run - That cross polar ridging is eerily similar to the ECM 240 chart.
Just wish this was the GFS 12z and not the much derided pub run.
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http://modeles.meteo...nh-0-192.png?18
GFS slowly edging along-
Great vertical WAA retrograding west ....
S
Shame it's the pub run and couple this with the ECM seemingly jumping ship for now - just viewed the ECM 12z ensembles.
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The met office's probability maps have updated today for the final time before winter begins
850 hpa Temperature has a 40% chance of been below normal
Precipitation
Sea level pressure has a 40% chance of been above normal
I have followed these probabilty maps for the last few years and I have always been able to draw a conclusion from them.
That is untill this years November update. It screams fudge to me, especially with the precipitation maps. How can you
have splodges of blue interspersed in close proximity with deep yellows!! My belief is that the Meto have blinked first.
Blinked before the ECM seasonal forecast. These two forecasts were at total odds with each other untill this latest Nov update
from the Meto. It suggests to me that there are far more conflicting signals this winter than usual and maybe even the supercomputers
are having a headache with it all.
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http://www.meteociel...cfse_cartes.php The latest CFS daily is certainly very blocked for December however as we all know this model changes run to run.
Just looked through that and my word, what an absolutely stonking Christmas that would be - magical.
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Well, the met probability charts still show a slightly below average winter temperature wise as the most likely outcome as
opposed to average or above. The fact that the pressure ensembles do not marry up to the likely temperature outcomes is,
quite frankly, unnacceptable as far as I am concerned. There should be a clear correlation between the two. The fact that
they do not simply fudges the seasonal forecast and totally detracts any sense of clarity for any lay person reading the seasonal forecast.
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It's a shame that the ECM doesn't go any further than 240 as I believe energy would undercut the high to our east.
Also, just look at that cross polar ridging from the pacific right through to Svalbard on the 240 chart - pretty impressive.
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Thanks I've come out of hibernation !
In terms of the BOM although its based on the UKMO model it has a lower resolution so best take that into account.
I should add a note of caution to the ECM, to get to 240hrs you need a good starting position within 144hrs re how it holds troughing further west with less energy into Scandi.
The UKMO isn't as good although much better than the GFS, we'll have to see whether those pull the pattern further west tomorrow.
Totally agree Nick. As ever, everything seems to be on a knifedge. In subsequent runs, we need to see the block to the east drift
west a little quicker and the troughs from the west dig south quicker. It would be great to see this trend but the models do not like
to make things easy for us!!
Lets have a bit of fun-
On every person that posts up to the ECM ensembles are released for day 15
how many snow spikes will be seen on the KNMI link -
I will go for 8.
http://www.knmi.nl/e...agse/index.html
Currently 4.
S
I will go 9 Steve
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All eyes now on the ECM 12z ensembles. We will be able to see how much support there is for the operational.
Only yokin!!
Winter Model Discussion - The Hunt For Cold -12z 14/12/12
in Spring Weather Discussion
Posted
120 hr fax chart is great, no sign of azores high.